A defogger and a glass antenna which are arranged on a rear window glass of a vehicle (e.g. an automobile) are already known. The defogger has printed heater wires. When a current is supplied to the heater wires, the defogger may defog the rear window glass. The glass antenna has printed conductive wires. For example, the glass antenna may receive FM radio broadcasts.
One of known glass antennas has a plurality of antenna elements and a feeding terminal. One of the antenna elements is a first antenna element formed from conductive wires printed on a rear window glass. The feeding terminal is connected not only to the first antenna element but also to a receiver through an antenna amplifier. The other two of the antenna elements are connected to the feeding terminal. A second antenna element is set so as to receive radio broadcasts in a frequency band different from a third antenna element. For example, the second antenna element is set so as to receive FM radio broadcasts having a frequency band of 88 to 108 MHz whereas the third antenna element is set so as to receive digital radio broadcasts (DAB) having a frequency band of 174 to 240 MHz.
Patent Document 1 discloses a glass antenna having a feeding terminal, a first element and a second element. The feeding terminal is connected to an antenna amplifier. The first and second elements are connected to the feeding terminal. The second element includes a main body portion extending from the feeding terminal; and a fold-back portion which is folded back from an end portion of the main body portion so as to be arranged along the main body portion. The glass antenna of Patent Document 1 may receive FM radio broadcasts and digital radio broadcasts.
If an FM antenna and a digital radio antenna are connected to one feeding terminal, an antenna amplifier and the feeding terminal are shared by the FM antenna and the digital radio antenna. Accordingly, a glass antenna may be formed from fewer parts. In addition, the glass antenna does not require an excessively wide arrangement region. However, a structure in which the FM antenna and the digital radio antenna are connected to one feeding terminal is more likely to face a risk of reducing receipt sensitivity than a structure in which antenna amplifiers and feeding terminals are individually allocated to the FM antenna and the digital radio antenna.